Modern networked applications have increasing needs for data communication on the network. Generally, this data falls into two categories: (1) small control messages such as web browser requests or remote procedure calls; and (2) large data messages such as video files and other multimedia documents. Communication between two networked applications takes place over a network connection. A problem arises when an application needs to send a small data message while the network connection is being used to send a large message such as an 8 mega-pixel image, especially when transfer of the small data message is time-sensitive.
One existing solution to this problem is for the application to use two network connections: one for small control messages, and the other for large data messages. This solution is employed by the FTP (File Transfer Protocol) standard. The drawback with this solution is in the overhead and inefficiency of using a second network connection. Control messages are typically sent infrequently, resulting in the second network connection being under-utilized. A second solution is for the application to wait for the large message to be sent, and then send the smaller control message. While this is acceptable for some application needs, if the control message is time-sensitive this solution is inadequate.